During the last pluvial period, about 20,000 years ago, a great lake called the Lake of Lisan covered the region. Because of its sheltered location, low elevation, and the influence of the lake itself, the winters are mild, with temperatures averaging 57 °F (14 °C) in January.The absence of freezing temperatures has facilitated the cultivation of bananas, dates, citrus fruit, and vegetables.The greatest part of the region is covered by basalts that have been formed since the Miocene Epoch (about 23 to 5.3 million years ago) and that are part of the vast area of Mount Durūz, located in Syria.

It is famous for its biblical associations; its Old Testament name was Sea of Chinnereth, and later it was called the Lake of Gennesaret.The summers are hot, with temperatures averaging 88 °F (31 °C), and the precipitation—almost 15 inches (380 mm) at Deganya—falls, in the course of a winter of less than 50 days, in the form of brief but violent showers.The Sea of Galilee is fed primarily by the Jordan River.The Jordan Valley is part of the East African Rift System, which forms the deep trench through which a tributary of the Jordan River passes to the east of the lake.Smaller and less-important faults occur to the west.